Assembly Biosciences Initiates Phase 1b Clinical Trial Evaluating Next-Generation Core Inhibitor

Assembly Biosciences, Inc. recently announced the initiation of a Phase 1b trial of its investigational next-generation, highly potent core inhibitor ABI-H3733 (3733).

3733 has demonstrated significantly increased potency against covalently closed circular DNA (cccDNA) formation and new virus production as compared to first-generation core inhibitors in preclinical studies, consistent with the company’s strategy to optimize its next-generation candidates for antiviral activity against both mechanisms. This trial builds upon the results of a previous Phase 1a study of 3733 showing a favorable safety and pharmacokinetic profile and will evaluate a new tablet formulation with the potential for convenient once-daily dosing.

“We look forward to better understanding the safety profile and impact of activity of this novel, next-generation core inhibitor candidate in patients with chronic HBV infection through this trial,” said John McHutchison, AO, MD, Chief Executive Officer and President of Assembly Bio. “This study initiation serves as an important milestone in the clinical development program for 3733, a promising candidate that has demonstrated increased potency against both HBV core inhibitor mechanisms and against cccDNA formation in particular, and advances our strategy to pursue finite and curative HBV therapies.”

The Phase 1b clinical trial is a randomized, multi-center, double-blind and placebo-controlled study that will evaluate the safety, pharmacokinetics and antiviral activity of 3733 in adults with chronic HBV (cHBV) infection. The dose-escalation trial will enroll approximately 50 patients with diagnosed cHBV infection who are treatment naïve or who are off treatment. Patients will be randomized 8:2 between the new tablet formulation of 3733 and placebo for a period of 28 days. The objectives of the study include assessments of safety, tolerability and pharmacokinetics of 3733 in patients with cHBV infection, as well as changes in HBV DNA and other viral parameters associated with 3733 treatment. Results of the trial will support dose selection for a future Phase 2 trial.

Additional information about the Phase 1b clinical trial will be available at www.clinicaltrials.gov. Additional details about the new tablet formulation of 3733 will be provided in a poster accepted for presentation at the International Liver Congress (ILC), the Annual Meeting of the European Association for the Study of the Liver (EASL), taking place virtually and in person in London on June 22-26, 2022.

Assembly Bio is a clinical-stage biotechnology company committed to bringing finite and curative therapies to the 296 million people living with hepatitis B virus (HBV) worldwide. A pioneer in the development of a new class of potent, oral investigational core inhibitors, Assembly Bio’s approach aims to break the complex viral replication cycle of HBV to free patients from a lifetime of therapy. Assembly Bio’s strategy includes a leading portfolio of more potent, next-generation core inhibitor drug candidates, proof-of-concept combination studies for HBV cure and research programs focused on the discovery of additional novel antiviral mechanisms for HBV and other viral diseases. For more information, visit assemblybio.com.